Add a new remote called all that we'll reference later when pushing to multiple repositories:
$ git remote add all git://original/repo.git
$ git remote -v
all git://original/repo.git (fetch) <-- ADDED
all git://original/repo.git (push) <-- ADDED
origin git://original/repo.git (fetch)
origin git://original/repo.git (push)
$ git config -l | grep '^remote\.all'
remote.all.url=git://original/repo.git <-- ADDED